The present invention relates to a method of making reinforced hinge covers for three ring binders and the like and especially to hinged covers having a polymer covered panel with polymer reinforced hinge portions
Typical prior art patents can be seen in the Torti U.S. Pat. No. 4,863,331 for a method of making half-binding hard covers for books and a machine for the implementation thereof and in the Podosek U.S. Pat. No. 4,600,346 for a binder cover and method of manufacturing the same having a unitary web of thermal plastic sheet material wrapped about and easily bonded over the binder panels. The Carter et al. U.S. Pat. No. 4,405,156 shows the making of a reinforced hinge for a book cover using a reinforced member secured to the edges of the leafboard of the book cover. The Peterson et al. U.S. Pat. No. 2,758,631 shows an apparatus for making plastic covers in a conventional three ring binder method which simultaneously heats and seals similar plastic sheets with stiffeners therebetween.
The present invention, on the other hand, teaches a method for cutting parallel cuts in a stiffening panel and stripping the area between the cuts from a large stiffening panel while attaching a reinforcing polymer strip over the stripped away area of the panel to hold the panel sections in a predetermined spaced relationship to each other with a defined spacing for the hinge and then covering at least one side with a polymer sheeting and then sealing the polymer reinforcing and spacing member and the polymer cove along the hinge line to form a defined reinforced hinge for a book cover or three ring binder.